Background: Cardiogenic shock (CS) is a severe complication of acute myocardial infarction (AMI) with high mortality rates. While mechanical circulatory support devices like intra-aortic balloon pump (IABP) and Impella are used to manage CS, their comparative effectiveness remains unclear. This meta-analysis aims to evaluate the safety and efficacy of Impella in the treatment of AMI-associated CS.
Methods: A comprehensive literature search was performed across PubMed, EMBASE, Google Scholar, SCOPUS, and Web of Science. The primary efficacy endpoint was 6-month all-cause mortality. Secondary efficacy endpoints included 30-day mortality, major bleeding, limb ischemia, sepsis, and left ventricular ejection fraction. Pooled odds ratios (OR) and standardized mean difference (SMD) with 95% confidence intervals (CIs) were calculated using the random-effects model via Revman version 5.4. Statistical significance was determined at P < .05.
Results: Four RCTs with a total of 442 patients were included in this meta-analysis. The pooled analysis showed that the odds of 6-month all-cause mortality were significantly lower with Impella compared to standard of care (OR: 0.64, 95% CI: 0.43-0.95; P value: .03). However, 30-day mortality reported no statistically significant difference between the 2 groups (OR: 1.03; 95% CI: 0.43-2.48; P = .95). Our analysis found that the use of impella is associated with a statistically significant increase in the odds of major bleeding (OR: 3.61; 95% CI: 1.14-11.40; P = .03), limb ischemia (OR: 4.91; 95% CI: 1.37-17.59; P = .01), and sepsis (OR: 2.75; 95% CI: 1.25-6.08; P = .01). No statistical significance was found in left ventricular ejection fraction at follow-up between the 2 groups (SMD: -0.35; 95% CI: -0.78 to 0.07; P = .11).
Conclusion: Impella significantly reduces 6-month all-cause mortality in patients with CS following AMI compared to standard of care. However, this survival benefit is offset by a substantial increase in major bleeding, limb ischemia, and sepsis risks associated with Impella. Future large scale trials are needed to validate these findings and refine clinical guidelines for the optimal use of Impella in treating CS.
